Table 1 Categories, criteria, and coding used for museum trees
From: Communicating Phylogeny: Evolutionary Tree Diagrams in Museums
Category | Description and coding |
|---|---|
Topological and diagrammatic elements | |
Orientation | Overall orientation of tree, or the position of the root relative to branches. Those with no overall orientation (e.g., circular or radial geometries) were coded as N/A |
Direction | Overall direction of branches from the root; circular trees were coded by the direction of the initial spiral, and radial trees were coded N/A |
Geometry | Trees classified as a cladogram and “almost-a-cladogram” were coded as angled, rectangular, curvogram/swoopogram, circular, radial, or eurogram. Non-cladistic/other evolutionary trees, were coded as N/A |
Terminal branch end points | Whether branches end at different levels |
Images of taxa | Taxa are represented visually (graphically through images, silhouettes, or with models/specimens) |
“Tree of life” | Diagrams has a central main trunk with taxa branching off of it with a clear linear progression from “lower” to “higher” forms (Haeckel 1874) |
Tree content | |
Anagenesis | Depicts ancestor–descendant relationships between named taxa (e.g., genus or species) with one or more named taxa in a sequence along a branch |
Taxa | Invertebrates, vertebrates, broad taxonomic categories, or other (e.g., viruses) |
Extinct taxa | Includes extinct taxa |
Humans and their most recent extinct relatives | Includes one or more members of this group |
Geological time | Includes an indication of time |
Classification | Explicit links between parts of tree and more familiar classifications of organisms |
Common ancestor | Refers to one or more common ancestors |
Synapomorphies | Synapomorphies (shared characteristics) are indicated |
Hybridization | Includes lateral transfers of genetic material, i.e., it represents a phylogenetic network in which hybridization or similar events are believed to have been involved, rather than a tree that only depicts branching sequence |
Presentation and explanation | |
Exhibit component | Static flat graphic panel, graphic backdrop for specimens/models, 3D representation, media component (e.g., video or game in kiosk/online), or a supplemental document |
Instructional information/interpretation | Provides an explanation of what the tree shows (e.g., refers to relationships between taxa, describes changes or trends over time), instructs how to interpret evolutionary diagrams (e.g., describes trees as branching diagrams that show relatedness) |
Nature of science | Labels or legends include information about the data used to build the tree, refers trees as hypotheses or product of scientific reasoning |